Aims: Alloimmune response to red cell transfusion has not been widely investigated in pediatric patients. We retrospectively compared the frequency and specificity of red cell antibody formation among pediatric recipients grouped by age, versus an adult control cohort.

Methods: A total of 331 pediatric red cell transfusion recipients were studied in four age groups: 0 to 4.9 months (Group A), 5.0 to 11.9 months (Group B), 1.0 to 5.9 years (Group C), and 6.0 to 14.9 years (Group D). Similarly transfused adult males, 20.0 to 59.9 years old, as a control cohort group. Alloimmunization was defined as post-transfusion detection of red cell alloantibodies not detected prior to transfusion.

Results: After red cell transfusion, no one in Group A (0 of 106) developed alloantibodies, whereas 8.0% (2 of 25) in Group B, 1.1% (1 of 95) in Group C, and 2.9% (3 of 105) in Group D, versus 2.1% (8 of 380) of adult male controls who developed alloantibodies. However, these differences did not achieve statistical significance.

Conclusion: This investigation of alloimmunization in pediatric recipients found no cases in patients younger than five months old, however, the incidence rates of older age groups were statistically indistinguishable from a control cohort of male adults. Until larger studies suggest otherwise, current antibody screening and cross-matching policies should be continued.

Author Contributions
Maiko Abe – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published
Hitoshi Ohto – Substantial contribution to conception and design, Analysis and interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published
Keiji Minakawa – Substantial contributions to conception and design, Acquisition of data, Analysis and interpretation of data, Drafting the article, Final approval of the version to be published
Kinuyo Kawabata – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Satoshi Ono – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Nozomi Takano – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Hiroe Suzuki – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Mao Watanabe – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Akiko Sugawara – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Masami Kikuchi – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Saori Miura – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Mao Watanabe – Substantial contributions to conception and design, Acquisition of data, Drafting the article, Final approval of the version to be published
Chikako Takeuchi-Baba – Substantial contribution to acquisition of data, Drafting the article, Final approval of the version to be published
Hiroyasu Yasuda – Substantial contribution to conception and design, Acquisition of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published
Kenneth E. Nollet – Substantial contribution to interpretation of data, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published
Yoshiko Tamai – Substantial contribution to conception and design, Drafting the article, Final approval of the version to be published
Junichi Kitazawa – Substantial contribution to conception and design, Drafting the article, Revising it critically for important intellectual content, Final approval of the version to be published
Kazuhiko Ikeda – Substantial contribution to conception and design, Drafting the article, Final approval of the version to be published

Guarantor of Submission
The corresponding author is the guarantor of submission.

Source of Support
None

Consent Statement
Written informed consent was obtained from patients prior to transfusion.